Some of Hampshire and the Isle of Wight Butterflies on the Red List 2022
Small Pearl-bordered Fritillary
Duke of Burgundy
25 May 2022
Wildlife charity Butterfly Conservation is warning that time is running out to save some of Britain’s best-loved insects, with the latest Red List assessment of butterflies published today, revealing a 26% increase in the number of species threatened with extinction.
Using data gathered by volunteers through the UK Butterfly Monitoring Scheme and Butterflies for the New Millennium recording scheme, scientists from Butterfly Conservation have put together the new Red List, which assesses all the butterfly species that have bred regularly in Great Britain against the rigorous criteria of extinction risk set out by the International Union for Conservation of Nature (IUCN). The new Red List is published today in the journal Insect Conservation and Diversity.
Of the 62 species assessed, four are extinct in Britain (Black-veined White, Large Tortoiseshell, Large Copper, and Mazarine Blue) with 24 (41% of the remaining species) classed as threatened (8 Endangered, 16 Vulnerable) and a further five (9%) as Near Threatened.
Head of Science for Butterfly Conservation, Dr Richard Fox, says: “Shockingly, half of Britain’s remaining butterfly species are listed as threatened or Near Threatened on the new Red List. Even prior to this new assessment, British butterflies were among the most threatened in Europe, and now the number of threatened species in Britain has increased by five, an increase of more than one-quarter. While some species have become less threatened, and a few have even dropped off the Red List, the overall increase clearly demonstrates that the deterioration of the status of British butterflies continues apace.”
While land-use change remains the most important driver of decline, the impact of climate change on butterflies is also evident in the new Red List, with all four British butterflies with northerly distributions, adapted to cooler or damper climates, now listed as threatened (Large Heath, Scotch Argus, Northern Brown Argus) or Near Threatened (Mountain Ringlet).
Both the Large Heath and the Grayling have moved from Vulnerable to Endangered, and seven species have moved from Near Threatened to threatened, including the beautiful Swallowtail and Adonis Blue. Two new species have been added for the first time, Scotch Argus, which is listed as Vulnerable, and Dark Green Fritillary, listed as Near Threatened.
The focus of concentrated conservation efforts
It isn’t bad news for all butterfly species though, with some improvement in status for those that have been the focus of concentrated conservation effort, offering hope for other species.
The Large Blue, which became extinct in Great Britain in 1979 and has been the subject of an intensive, ongoing, and highly successful reintroduction programme, has moved from Critically Endangered to Near Threatened. The High Brown Fritillary, also formerly listed as Critically Endangered, has moved to Endangered; likely to be the result of intense conservation work from Butterfly Conservation alongside other organisations. The Duke of Burgundy and Pearl-bordered Fritillary, which have also benefited from much targeted conservation effort, both moved from Endangered to Vulnerable.
Dr Richard Fox adds: “Where we are able to target conservation work, we have managed to bring species back from the brink, but with the extinction risk increasing for more species than are decreasing, more must be done to protect our butterflies from the effects of changing land management and climate change. Without action it is likely that species will be lost from Britain’s landscapes for good, but Butterfly Conservation is taking bold steps to improve key landscapes for butterflies and reduce the extinction risk of many threatened species.”
The production of the new Red List of British butterflies has been led by Butterfly Conservation with input and funding from Natural England, and the full scientific paper can be found here: https://doi.org/10.1111/icad.12582
Dark Green Fritillary
UK butterflies vanish from nearly half of the places they once flew – study
Butterfly Conservation report reveals 42% decline in distribution of 58 native species since 1976
Butterfly species have vanished from nearly half of the places where they once flew in the UK since 1976, according to a study.
The distribution of 58 native species has fallen by 42% as butterflies disappear from cities, fields and woods. Those that are only found in particular habitats, such as wetlands or chalk grassland have fared even worse, declining in distribution by 68%.
Scientists for Butterfly Conservation, which produced its State of the UK’s Butterflies 2022 report from nearly 23m butterfly records, said there needed to be a “massive step-change” to reverse what it described as disastrous declines in insect populations.
The report shows that many of the most endangered species have been revived by targeted conservation action or successfully reintroduced in specific places, but butterflies and other flying insects continue to vanish from much of Britain.
“We’ve been focused on the most threatened butterfly species, which is stopping them going extinct,” said Richard Fox of Butterfly Conservation, the lead author of the report. “But there’s a massive challenge revealed by millions of pieces of data in the report, and we need a massive step change in our approach to tackle this and meet the legally binding government target that now exists for halting the decline of wildlife. This report shows we are not halting the decline of wildlife.”
The overall figure for the decline in butterfly abundance is a relatively modest 6%, but this average figure is obtained from data gathered from nature reserves and nature-rich landscapes, which masks wider population falls.
Species such as the wood white, grayling, wall, white admiral and pearl-bordered fritillary have suffered precipitous declines in both distribution and abundance. The grayling fell by 92% in distribution and 72% in abundance between 1976 and 2019.
There have been some successes, linked to climate change or concerted conservation action. Beneficiaries of global heating, which has facilitated their expansion further north through Britain, include strong-flying species such as the purple emperor, whose distribution is up by 58% and abundance by 110%, and the comma , whose distribution is up by 94% and abundance by 203%.
Conservation triumphs include the large blue, which was reintroduced using caterpillars from Sweden after its extinction in 1979. Its abundance has risen by 1,883%.
But in many cases, although targeted conservation work on certain nature reserves has increased the abundance of rare butterflies, they have continued to vanish from other places, their range shrinking and their populations losing resilience as a result.
The swallowtail has increased in abundance by 51%, doing well on nature reserves which are precisely managed to meet its needs, but its distribution or presence in the wider landscape has shrunk by 27%. Chalk grassland specialists such as the silver-spotted skipper and adonis blue have increased in abundance by 596% and 130% respectively, but their distribution has fallen by 70% and 44%. This shows that they are no longer able to survive in a large proportion of their former haunts, nor are they able to colonise new areas.
The biggest butterfly declines are in England. The picture looks more positive in Scotland, where species have, on average, increased in abundance by 37% and in distribution by 3%.
But Fox said these figures were caused by the huge successes of a few species, such as the comma and the white-letter hairstreak, which have been able to move further north with climate change. “It’s not a cause for celebration,” he said. “Butterflies that you might think of as iconic examples of Scotland’s natural heritage such as the mountain ringlet, Scotch argus and northern brown argus are all doing really badly.
“UK butterflies are by far the best, most comprehensively monitored group of insects anywhere in the world. Butterflies are fulfilling that really important role as an indicator for thousands of other species and the general state of our environment. This report is very gloomy reading on that front.
“It’s going to need bold moves by government and everyone to take responsibility. Everyone with a garden can help, but the scale of the biodiversity crisis is such that planting a few pollinator-friendly plants is not enough. We need to create habitat where butterflies and other wildlife can live and not just visit for a snack.”
Julie Williams, the chief executive of Butterfly Conservation, said: “This report is yet more compelling evidence of nature’s decline in the UK. We are totally dependent on the natural world for food, water and clean air. We need swift and effective action on this. The decline in butterflies we have seen in our own lifetimes is shocking and we can no longer stand by and watch the UK’s biodiversity be destroyed.”